I'm not sure if HN tracks this, currently; it's pretty obvious that clicking on a story doesn't send you through an intermediate redirection page, which is the

I'm not sure if HN tracks this, currently; it's pretty obvious that clicking on a story doesn't send you through an intermediate redirection page, which is the simplest way to monitor that sort of thing, but there could be some fancy javascript stuff going on to register click-throughs. It's all in the source code, of course; if you want to go hunting for it, then by all means do so.